ISSN 2997-1036
International Journal of Hematology | Vol. 14, No. 3, March 2023 | pp. 17–24
DOI: 10.46882/2023/IJH/000157
Case Report
Title: Spontaneous massive retroperitoneal hemorrhage secondary to acquired Factor VIII inhibitor development in an elderly patient: Eradication with rituximab
Names of Authors: K. L. Musa¹, M. N. Lawal², O. P. Dikko³
Authors’ Affiliations: ¹Department of Haematology, Federal Medical Centre, Katsina, Nigeria; ²Department of Surgery, Bayero University, Kano, Nigeria; ³Department of Pathology, Ahmadu Bello University Teaching Hospital, Zaria, Nigeria
Abstract: Spontaneous development of neutralizing autoantibodies directed against coagulation Factor VIII is an exceptionally rare condition that causes catastrophic bleeding events in elderly populations. We report a 74-year-old male who presented with sudden, unprovoked left flank pain, lower abdominal distension, and hypovolemic shock. Abdominal computed tomography confirmed a massive retroperitoneal hematoma measuring 12.4 × 8.5 cm without prior trauma or anticoagulant exposure. Coagulation profiles demonstrated isolated, severe prolongation of activated partial thromboplastin time (88.4 seconds) with a normal prothrombin time. A 1:1 mixing study with normal pooled plasma failed to correct the activated partial thromboplastin time, indicating a specific intrinsic pathway inhibitor. Functional assays confirmed severely depressed Factor VIII activity (< 1.0%), and a Bethesda assay quantified a Factor VIII inhibitor titer of 24.5 Bethesda Units. Hemostasis was achieved using recombinant activated Factor VII bypassing agents (90 μg/kg every 3 hours) alongside supportive measures. Subsequent immunosuppressive therapy with high-dose corticosteroids was unsuccessful. However, a targeted rituximab protocol (375 mg/m² weekly for 4 weeks) successfully cleared the inhibitor (0 BU) and normalized Factor VIII activity by week 8. This case demonstrates that acquired Factor VIII autoantibodies require immediate diagnostic differentiation and multi-modal therapeutic strategies.
Keywords: Acquired factor VIII inhibitor, retroperitoneal hemorrhage, intrinsic pathway, bypassing agents, rituximab
Manuscript Timeline: Received: December 14, 2022; Revised: January 20, 2023; Accepted: February 12, 2023; Published: March 18, 2023